Indicating device



. May 29, 1928.

F. H. BUCKNGHAM I'NDIGATING DEVICE Filed Oct. 20, 1922 l regardless of perspective view Patented May 29, 1928.A i I UNITED STATES PATENT OFFICE.

PANY, OF TOLEDO, OHIO, A CORPORATION OF NEW JERSEY.

INDICATING DEVICE.

Application led October 20, 1922. Serial No. 595,800.

This invention relates to vindicating devices, and particularly to means for obviating errors'of parallax due to the position of the reader. v f K In weighing scales and other devices having automatic indicating mechanism, the indication is usually read by noting the .position of a relatively movable chart and index, and, since the index as a general rule is not in the plane of the chart, the particular figure or graduation of the chart with which the index appears to be in regist-ration varies to some extent with sitionf ofthe observer. It is an object of this invention to provide means capable of so registering\with chart indications that the apparent indication remains the same change in'the position of the observer.

Other-objects and advantages will be apparent from the following description, in which reference is hadto the accompanying drawings illustrating preferred embodiments of my invention and wherein similar reference numerals .designate similar parts throughout the several views.

In the drawings Figure Al is a frontl elevation of a chart housing of a weighing scale embodying my invention, part of the front plate being removed to show the illuminating device;

Figure II is a diagrammatic view illustrating the mode of operation of my device;

Figure IH isa vertical sectional view through the chart housing of a weighing scale embodying my invention in modified form;

Figure IVsis an enlarged fragmentary,-

showing certaln elements of my invention; y

Figure V is a similar view showing elements of still another form; and

Figure VI is a view similar to Figure lV showing another form of the invention, differing only slightly from that shown in Figure IV.

Referring to the drawings in detail, thel chart housing vl and the chart 2 of the scale are of a type in common use, the chart 2 consisting of a light cylinder having weight graduations and figures 3 and value graduations and figures 4 onits outer cylindrical surface, certain of such figures and graduations being visible through a window 5 which extends across the front of the housthe poing. When a load is placed upon the scale. the cylindrical chart 2 revolves to an extent proportional to the weight of the load,

so that figures and graduations which represent the weight of the load and its values 6o at various prices per pound are brought into position in which they are visible through the window 5. The height of the window is such, however, that figures and graduations above and below those representing the ex- 65 act Weight and values of the commodity are also visible.

In order to indicate the exact figures and graduations to be read, it has been the pracy tice in devices of this kind to stretch a thin 7@ wire or line horizontally across the housin inclose proximity to the chart and in suc position that when viewed through the window 5 the line appears to be in registration with certain figures and graduations. if@ When this device is employed, however, the figures with which the line appears to be in registration vary with the height of the observer, so that the weight and value graduations which appear to a tall observer to be in registration with the indicator line are not thesame asthose which appear to a short observer to be in registration with the line.

lin order to prevent such discrepancies in reading, l employ a transparent mirror through which one of the indicating elen cafnents to be brought into registration is visible, the other clement being reflected in the mirror, so that to the observer the two ele- 'ments appear to be in registration in the same plane.

ln the form of device shown in Figures I and II the chart is viewed through a pair of complementary prismatic strips of glass 6 and 7 arranged, as shown in Figure Il', so that the refraction of one of the prisms is substantially neutralized by the other and a ray of light emanating from the chart and passing through the prism leaves Nthe surface lof the outer prism in a direction substantially parallel to the direction in which it entered the surface of the prism nearest the chart. Graduations and figures on the chart viewed through the prisms 6 and 7 therefore appear to be in the same position as that in which they would appear to be if they were viewed through a plain sheet of glass with parallel faces. The upper face of the prism 7 is covered by an opaque strip 8, and the corner at which the outer and upper surfaces of the prism 7 intersect is preferably ground E -to form a very narrow flat surface 9, the width of such sur- -face being so slight that it forms, in effect,

a fine line. This narrow'surface 9 is not covered by the opaque strip 8. l

Mounted above the prisms 6 and 7 within the housing 1 are lamps 10, the front cover visibility of this line is,Y enhanced by covering the narrow surface' 9 with a transparent colored substance, such as a strip 12 of red Celluloid, so that the surfaceI .9 appears to the observer as a brilliant red, line lying horizontally on the face of the chart 2. The same effect may, of course, be secured by coating the narrow surface 9 with a film of colored material. 1- 'n y l In Figures III and IV the frontface of the prism 7a is shown as convex, so that the prism-also performsthe function of a lens tween the chart which magnifies the vertical dimensions of the chart characters that are viewed through itand increases the apparent distance beraduatio'ns, Ithus making the indication easler to read. The member 7a may perhaps more accurately be called a bar than a prism, since its sides are not all plane. v Prism is used to convey the idea of transparency, but it is to be understood that. transparent bars of various forms are included within the term. f Y

v In the form of .device shownin Figure V, the transparent; mirror consists of a -sheet 14; of transparent material having a reiiecting. surface, vsuch as glass .or Celluloid. /Above the transparent mirror 14 is placed a strip 15 of transparentfmaterial preferably colored-.for example, red glass or red celluloid-having one of its surfaces coated withopaque material 1 6 having a straight line 17 cut or scratched through it to permit the passage of light. In this form of the device, when. the chart 2 is viewed through the transparent mirror 14, the .v line 17 appears as a brilliant colored line lying upon the face of the chart 2. v v f Figure VI showsv a form^ of the device diiering from that shown in Figure IV only vin that thel line 9b is formed .not at the cortrated embodiments of my invention herein disclosed are well calculated to adequately fulfill the objects primarily stated, it is to lbe understood that the invention is suscepti-` ble to variation, modification and change within the spirit and scope of the subjoined claims. l

Having described my invention, I claim: 1. In an indicating device, in combination, relatively movable indicating elements, and a transparent mirror, the parts being so arranged that when one of said elements is view through the mirror an image of the other element appears coincident therewith. 2. In an indicating device, in combination, a relatively movable chart and index, and a transparent mirror, the parts being so arranged that when ysaid chart is viewed through said transparent mirror an image of said index appears upon the face of said chart. l y l 3.' In an indicating-device, in combination, a movable chart, a stationary indicator line,

.and a transparent mirror, the parts being so arranged that When said chart is viewed through said mirror an image of said line appears substantially coincident with the face ofV said chart.

4. In a device of the class described, in

combination, a chart, a transparent prism through which said chai-tis visible, and an index, the parts being so arranged that When saidv chart is viewed through said prism an image of saidindex appears by-reflection` from a surface of said prism to lie substantially coincident with the face of said chart.

5. In an indicating device, in combination, a chart, and a transparent prismthrough which the face of said chart is visiblegsaid prism having an index thereon, the parts being so arrangedthat when the said chart is viewed through' said prism an image ofthe index appears by reiiection. from a surface of said prism to lie substantially coincident with the face of said chart.

6. In an indicating device, in combination, a chart, and a transparent prism through which the face of saidA chart is visible, said4 prism having an index thereon, the parts' being so arrangedthat when the`said chart is viewed through said prism an image of' the` index appears by reflection from a surfaceof said prism to lie substantially coincident with the face of said chart, said index ybeing formed by a distinctive. narrow portion of the surface of said prism. y

7. In an indicating device, incombination, achart, and a transparent prism through which the face of said chart is visible, said prism having an index thereon, the parts being so arranged that when the said chart 1s `viewed through said prism an image of the index .appears 'by refiection from a surface of said prism to lie 'substantially coincident with the face of said chart, said index being formed by-a narrow transparent portion of the surface of said prism lying adjacent an opaque portion of the surfaceof said prism.

8. In an indicating device, in combination, a chart, a transparent prism through which the face of said chart is visible, said prism having an index thereon, the parts being so arranged that when the said chart is viewed through'saidprism an image of the index appears by refiection from a surface of said prism to lie substantially coincident with the face of said chart, said index being formed by a narrow portion of the surface of said prism,- and means for supplying colored light to said narrow portion.

9. Inan indicating device, in combination, a chart, and a transparent prism through which the face of said chart is visible, said prism having an index thereon, the parts being so arranged that when the said chart `s viewed through said prism an image of the index appears by reflection from a surface of said prism to lie substantially coincident with the face of said chart, one of thefsurfaces of said Vprism having a coating of opaque material, and said index being in the form of a slit in the said opaque material.

10. In an indicating device, in-combination, a chart, a bar of transparent material through which said chart is visible, said bar having-a-reflecting surface, and an index, the

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parts being so arranged that when saidy chart is viewed through said bar an image of the index appears by refiection fromv fleeting surface t0 lie substantially coincident witht'he face `of said chart.

11. In an indicating device, in VA'combinatlon, a chart, a bar of transparent material through which said chart is visible, said bar having' a reiiecting surface, and an index, the parts beingso arranged that when said chart is viewed through said bar an yimage of'imthe index appears by redection from said reflecting surface to lie substantially coincident with the tace of said chart, said index being formed by a distinctive narrow portion or the surface ot said bar.

12. In an indicating device, in combination, a chart, a bar of transparent material through which said chart is visible, said bar having a reflecting surface, and an index, the parts being so arranged that when said chart is viewed through said bar an ima e of the index appears'by reflection from said reiiecting surface to lie substantially coincident with the face of said chart, said index being formed by a narrow transparent portion of the surface of said bar lying adjacent the opaque portion of the surface of said bar.- f

13. In an indicating device, in combination, a chart, a bar of transparent materlal through which said chart is visible, said bar having a reecting surface, an mdex, the

said reparts being so arranged that when said chart is viewed through said bar an image of the index appears by reflection from said reflecting surface to lie substantially coi incident with the face of said chart, said index being formed by a narrow portion of the surface of saidbar, and means for supplying colored light to said narrow portion.

14. In an indicating device, in combination, a chart, a bar of transparent material through which said chart is visible', said bar having a reflecting surface, and an index, the parts being so arranged that when said chart is viewed through said bar an image of the index appears by reflection from said reecting surface to lie substantially coin cident with the face of said chart, one of the surfaces of said bar having a coating of opaque materiahaud ysaid index being in the form of a slit in the said opaque material. f y

l5.'- In an indicating device, in combination, a chart, a bar of transparent material through' which said chart is visible, said bar having a reflecting surface and a curved surface whereby the characters of said chart appear magnified as viewed through said bar, and an` index, the parts being so arranged that when said chart is viewed through said bar an image of the index appears by reection from said reflecting surface to lie substantially coincident with thejface of said chart.

16. In an indicating device, in 'combina-f tion, a chart, a bar of transparent material through which said chartis visible, said1 bar having a reflecting surface and a curved surface whereby the characters of said chart appear magnified as viewed through said bar? an index, the, par-ts'being so arranged that when said chart is viewed through said bar an image ef the index appears by reflection from said reiecting surface to lie substantiaily coincident with the face'o said chart, said index being termed by a narrow portion of the surface of said bar, and means for supplying colored light to said narrow portion.

i?. In an indicating device, incombination, a ,.chart, a bar of transparent materialv through which said chart is visible, said bar aving a redecting surface and a curved surface whereby the characters' of said 4face of said chart, one of the surfaces of said bar having'a coatingof opaque material, and said index being in'the form of a slit in thesaid opaque material.

18. In lan indicating *device, in combination, a chart, a pair ofcomplementary .transparent prisms through which said f chart is Visible, and an index, the parts being so 'arranged that when said chart is viewed through said prisms' an image of said index appears by reflection from a face of one of said prisms to lie substantially coincident with said chart.

19. In an indicating device, in combination, a chart, a pair of transparent bars through which said chartis visible, one of said bars having a reflecting surface, an index, the parts being so arranged that When the 'chart is viewed through said bars the prismatic effect of each bar is neutralized by that of vthe other, and an image of said index appears by reflection from a surface of one of said bars to lie.substan tiallyYV coincident with the face of said chart.

20. In an indicating device, in combination, a chart, a pair of transparent bars through which said chart is visible, one of said bars having a reflecting surface and a curved surface whereby the characters ofv said chart as viewed through said bars are magnified,- an lndex, the parts being so a1'- ranged that when the chart is fviewed through said bars the prismatic eect of each bar is neutralized by that of the other, and an image of said index' appears by re flection from a surface of one of said bars to lie substantially coincident with the face of said chart.

21. In an indicatingdevice, in co1nbina tion, a chart, a pair of transparent bars through which said chart is visible, one of said bars having a` reflecting surface and a curved surface whereby the characters of said Cchart as viewed through said bars are magnified, an index in the form of a nar-v row transparent surface on one of said bars, the parts being so arranged that when the chart is Viewed through said bars the prismatic effect of each bai is neutralized by that of the other, and an image of said index appears by reflection from a surface of onel of said bars to lie substantially coincidenti with the face of said chart.

.22. In an indicating device, in combination, a chart, a pair `of transparent' bars through which said chart isv'isible, one of amava vsaid bars having a reflecting surface and a curved surface whereby the characters of -said chart as viewed throughfsaid bars are means for supplying colored light to said index.

2K3. In an indicating device, in combination, a chart, a pair lof transparent bars through which said chart is visible, one of 'said bars having a reflecting surface and a curved surface whereby the vcharacters of said chart as viewed through said bars are magnified, a surface of one of said bars being coated with opaque material, an index in the form of a narrow opening in said opaque material, the parts being so arrange that when thel chart is viewed through saidbars the prismatic effect of each bar is neutralized by that of the other, and an image of said index appears by reflection from a surface of one of said bars to lie substantially coincident with the face of said chart.

24. Inan indicating device, in combination, a chart, a pair of transparent bars through which said chart is visible, one of said bars having a reflecting surface and a curved surface whereby the characters of said chart as viewed through said bars are magnified, a surface of one of said bars being coated with opaque material, an index in the form ofa narrow opening in said opaque material, the parts being so arranged that when the chart is viewed othrough said bars the prismatic effect of each bar is neutralized by that of the other, and an image of said index appears by refflection from a surface of one of said bars Vto lie substantially coincident with the face of said chart, and means for supplying colored light `to said narrow opening.

FREMONT H. BUCKINGHAM. 

